Global Overview of Actions Taken to Prevent SAI on VMEs: Surveys and VME Identification

Global Overview of Actions Taken to Prevent SAI on VMEs: Surveys and VME Identification

Scientific surveys have played a critical role in the identification of VMEs on the east coast of Canada and in the Northwest Atlantic Fisheries Organization (NAFO). The surveys have been used to identify VME indicators present, to map their distributions and determine where significant concentrations occur. Targeted surveys have been conducted to validate models and to collect new information on VMEs. This has occurred both within Canada, and within NAFO where Spain and Canada led a multinational/multidisciplinary survey effort to collect new information on VMEs.

NAFO is unique amongst RFMOs in that it has identified significant concentrations of VME indicators based on a combination of high biomass and discreteness of the area occupied, assessed using geospatial tools. These significant concentrations of large gorgonian corals, small gorgonian corals, sea pens, and sponges are considered to be the VMEs (NAFO 2013). Canada has also used this approach to identify significant benthic areas (SBAs) for coral and sponges under their equivalent domestic policy (DFO 2017). Biomass data for the analyses were from depth stratified random trawl surveys conducted by Canada and the EU. These surveys have been recording coral and sponge catch for over a decade and use VME species identification guides that were developed to improve the quality of the data.

Kernel density estimation (KDE) was the primary approach used to identify the general location of the significant concentrations of VME indicators (Kenchington et al. 2014, Kenchington et al. 2016). Area-catch weight curves were used to identify the weight thresholds defining the significant concentrations. Species distribution modelling was then used to interpolate between survey trawl locations within the VME polygons to further refine the delineation of the VMEs. For many of the areas, in situ observations were then made to validate the VME presence.

Identification of VMEs then allowed for an assessment of overlap with fisheries as the closed areas do not protect all of the VME. This has been done both in Canada (logbooks and VMS) and NAFO (VMS). NAFO is further exploring the impact of fishing on the VME outside of the closed areas using a modelling approach. At the same time two EU Horizon 2020 projects are undertaking research to learn more about the ecosystem function of coral and sponge VME. This information will be used to examine potential for ecosystem impacts in future.